BLUE LIGHT EMITTING DIODE

摘要

PURPOSE:To contrive high efficiency and long life by continuously growing epitaxially by using chlorine as the dopant of n-type ZnSe and nitrogen as the dopant of p-type ZnSe. CONSTITUTION:The reason why GaAs is used for a substrate 1 is that the lattice constant is nearly the same as that of ZnSe and that the excellent single crystal layer of the ZnSe can be grown epitaxially. An appropriate impurity is evaporated with a crystalline matrix material ZnSe and a chlorine-doped N-type ZnSe layer 2 and a nitrogen-doped P-type ZnSe layer 3 are continuously grown in sequence by changing the sort of the impurity. The electron density of the chlorine-doped N-type ZnSe layer 2 is made 5X10<16>cm<-3> or more to obtain high efficiency. If excessive chlorine is doped, a deep level is formed in band energy and the light emission except blue is made stronger so it is required to restrain the addition of the chlorine to an extent of electron density 5X10<18>cm<-3> or less. The thickness of the chlorine-doped N-type ZnSe layer 2 is made 1mum or more.